Pickup trucks are motor vehicles with a front passenger area, often referred to as a cab, and an open top rear cargo area, often referred to as a box. The box usually has a substantially flat bed from which two side body panels and a forward interconnecting header extend upwardly therefrom. Pickup trucks may also employ a bottom hinged door, commonly referred to as a tailgate, hinged at the rear edge of the bed and closable to provide a fourth wall for the cargo area. Cabs and boxes may be separate assemblies or part of the same unibody structure. Pickup trucks are popular largely because the box allows them to be utilized in many different ways, including carrying a variety of types of cargo and towing various types of trailers.